igneous
Peridotite (Dunite)
Peridotite / Ultramafic Igneous Rock
Hardness 6.5-7 (Mohs scale), olive-green to yellowish-green color, vitreous to dull luster, granular sugary texture, poor cleavage, high specific gravity (~3.1-3.4)
Identified More igneous →
Explore Peridotite (Dunite) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness 6.5-7 (Mohs scale), olive-green to yellowish-green color, vitreous to dull luster, granular sugary texture, poor cleavage, high specific gravity (~3.1-3.4)
Formation & geological history
Formed deep within the Earth's upper mantle through slow cooling of ultramafic magma. Often brought to the surface via tectonic uplift, obduction (ophiolites), or volcanic pipe eruptions.
Uses & applications
Primary source of chromium, platinum group elements, and peridot gemstones (gem-quality olivine). Also researched for carbon dioxide sequestration due to its high reactivity with CO2.
Geological facts
Peridotite makes up the vast majority of Earth's upper mantle. Diamonds are often carried to the surface within a specific variety of peridotite called kimberlite.
Field identification & locations
Identified by its rich olive-green color (due to high olivine content) and heavy, dense, granular texture. Commonly found in ophiolite complexes, mantle xenoliths, and greenstone belts worldwide.
